Re: re 6-8 Sv does not seem to be consistant with the reported symptoms

[g2v13a@swbell.net]

Thanks Richard, you have confirmed what I thought that I remembered.
(It is great that you still can find your copy of ANL-88-26 ... I am
still
looking for mine.)
:-)
Doug Jackson
Justanoldguyonthemedicalside
g2v13a@swbell.net

RadMax wrote:

> Doug J. Wrote>Greetings,.....
> >Based upon my observations of these patients over the years, I am
> suprized to
> >be hearing that 6-8 Sv in one exposure of less than one hour can
> cause death
> >within 6 hours or severe cns (etc.) symptoms within 8 hours.
> Admittedly, I
> >have dealt only in fractionated x-ray (medical) exposures.  My
> questions are
> >(for this type of event) :
> >1) What is the likely dose to the three persons described in the
> media
> >reports ?
> >(6-8 Sv does not seem to be consistant with the reported
> symptoms.).....
> >Just a "medical-type" trying to better understand a non-medical type
> event.Just a little refresher for those like me who actually had to
> look this up...In other words, how often do we need to remember this
> stuff??? PER:  Operational Health Physics Training   ANL-88-26 (MOE
> Manual)Chapter 5 Section E Early Somatic Effects - Acute Radiation
> Syndrome .....For very high whole body doses, there are three basic
> forms of early or acute damage.  In the range above about 20 Gy (2000
> rad), the dose is fatal within a day or two.  The same symptoms appear
> when the head suffers sever irradiation, which point to a breakdown of
> the central nervous system.  This type of acute radiation syndrome is
> thus referred to as central nervous system death (CNS death).      For
> the range 5 - 20 Gy (500 -2000 Rad), symptoms may appear within
> hours.  Death occurs within a week or so.  In this mode, the damage to
> the lining of the intestinal tract is the most severe.  This from is
> called gastrointestinal tract death (GI death).  At the lower end of
> this dose range, it is possible for one to survive this mode of death
> only to fall victim to the effects which prevail at lower doses.
> At doses < 5 GY (500 rad), the most important effect is damage to the
> blood forming organs.  Since these centers are located in the bone
> marrow, this mode of death is often called bone-marrow death.  The
> first signs may appear within a few days, depending upon the dose, and
> the total effect may not develop for a few weeks.  Sever changes occur
> when the dose is >2 Gy (200 rad).  In the range above 3 Gy (300 rad),
> the damage is severe enough so that death becomes more and more
> probable. ......Death occurs in a larger fraction of cases as the dose
> increases.  If the dose becomes large enough, all cases of exposure
> result in death.  In the range where survival is possible, the concept
> of the median lethal dose (LD50) is used.  For man, the best estimate
> places the LD50 in the range of 3 to 5 Gy (300-500 rad).  Of course,
> in this range all would have severe symptoms.  NOTE that this dose
> REFERS TO SHORT-TERM TOTAL BODY RADIATION (emphasis is mine).
> Lethal Dose 50/30 (50% casualties within 30 day - no medical
> treatment) is typically given as 450 Rem (450 rad or 4.5 Sv OR 4.5 Gy)
> acute dose.  And the LD 50/60 is estimated to lie in the range 2.5 to
> 5 Gy  As Ray wrote in answer to Chris "Yes, it would be more correct
> to use Gray".  The concept of dose equivalence does not apply to acute
> exposures greater than about 15 Rem.  Of course, I'm sure the
> community as a whole has learned much more about effects and the ways
> of treatment thanks to Chernobyl since the above sections were
> written. How about it Argonne, can we expect a more up to date 'MOE'
> any time soon? Richard Urban
> Jr.JustalowlifecontractradiationprotectiontechnicianscumAiken, SC

************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html